I also got mine yesterday. Registered for a Square Enix account, linked my PlayOnline ID to my SE ID, registered my token via serial number and one time password.
After I logged in (twice), my mog satchel became available. Here's the deal:
When you bring up your inventory, it's the same size and you can't see the satchel. In order to use the satchel, you have a new command:
/satchel
Using this command brings up the satchel and your inventory window, side by side. You can sort each window separately and transfer items between them in the field. Essentially it's like carrying a mog bank around with you.
Currently my satchel contains all my fishing gear and lures, all my crystals, a couple long-term quest items like a delkfut key and pirate chart, and some farmed items like lizard eggs etc. I have Gobbie Bag VII, so my inventory has 65 slots, and thus my satchel also has 65 slots. Very comfortable to have all that extra space.
One note: the playonline viewer will not let you save your SE password. So each time you log in you must enter both your password (via soft keyboard) as well as the one-time token password.